E girardeatt and joseph bethenod



E. GIRARDEAU AND J. BETHENOD. DEVICE FOR AUXILIARY STARTING'FOR HIGHPOWER RADIOTELEGRAPHIC STATIONS.

APPLICATION FILED MAR- !6. 1916- Patented Aug. 12, 1919.

EMILE GIRARDEAUAND JOSEPH BETHENOD, OF PARIS, FRANCE.

DEVICE FOR AUXILIARY STARTING FOR HIGH-POWER RADIOTELEGRAPHIC STATIONS.

Specification of Letters Patent.

Patented Aug. 12, 1919.

Application filed March 16, 1916. Serial No. 84,668. I

To all whom it may concern:

Be it known that we, EMILE GIRARDEAU and Josnrrr BETHENoD, residing inParis, France, 10 Rue Auber, have invented a new and useful Improvementin Devices for Auxiliary Starting for High-Power RadiotelegraphicStations.

Auxiliary excitation systems in radiotelegraphyv are known, theirobjectbein' to regulate the discharge in the main osci lating circuit ofhigh power radio-telegraphic apparatus.

The present invention relates to improved means whereby suitableexcitation of the auxiliary circuit is effected from a source ofalternating current of high frequency preferably of 500to 1000 periods.The means hereinafter described have the advantage of being capable ofadaptation generally without it being necessary to provide an auxiliarysource for the excitation,.the auxiliary spark gap being fed by the mainsource.

Moreover, the auxiliary spark gap is discharged-at low power about 6% ofthat of the main discharge and is'not traversed by the main current.

The accompanying drawing illustrates, by the way of examples, twoembodiments of the invention: Figure l is a circuit diagram illustratinga system of generating electric waves for wireless telegraphy, and Fig.2 is .a diagram of a slightly modified system; C is the condenser of themain oscillating circuit and is charged at high tension by means of atransformer T, the primary winding of which is fed by thealternatingcurrent generator A in'accordance with any known method; the main sparkgap E of known type, is adjusted so that the maximum voltage at theterminals of the condenser C is insuflicient to produce alone anoscillating discharge in the circuit CE S.

In order to obtain the spark discharge at E at very regular intervals, acircuit K 1' Z is provided in parallel with the condenser C, K being acapacity, 1" an adjustable ohmic resistance and Z an adjustableinductance.

Owing to the provision of this circuit the charge of the condenser K maybe slightly in advance of that of the condenser C. An adjustableinductance s is connected inductively with the inductance S. If anauxiliary spark gap indicated at e is suitably adjusted the oscillatingdischarge of K through the inductance 8 produces in the inductance S aninduced voltage which is added at E to that producer by thetransformerat the terminals of the condenser O the discharge at E- thus beingeffected at the precise moment when the voltage at O is at its maximum,if the constant dimensions of the difi'erent circuits are suitablychosen. The auxiliary from the alternating current generator A asindicated by the gears R and P. This solution is advantageous in view ofthe mod-,

erate power for the production of the auxiliary spark. The higher thecircumferential speed of this disk the smaller the di-' ameter of thedisk may be held. This gear transmission necessitates a certain amountof play between the toothed wheel R keyed on the alternator shaft andthe pinion P keyed on the shaft of the spark gap 6; it follows thereforethat the phase of the spark relative to the voltage at the terminals ofthe condenser C with respect to the times when the sparking distancesare at a minimum at 6, may vary with the reduction in speed of thealternator. Owing to its comparatively high inertia, the rotary sparkgap disk tends to oppose a decrease in speed more particularly those dueto varlations of the periodic charges during. emisslon, and it isdlificult to completely avoid this. In order to eliminate thisdisadvantage which may render the operation of the auxiliary spark gapvery irregular, it is'advisable to counterbalance the tendency of therotary disk t9 pick u speed in the periods of spark discharge in t emain spark gap.

The simplest solution i then to couple or connect the rotary disk with agenerator D. This generator may ciated with the generator A and maysupply the direct current for the field of the main alternator. It isobvious that the load of this generator will, if necessary, be 1ngreasedautomatically at each emission of a signal, that is to say at eachdecrease of the speed of the main alternator. It is well known in theart of wireless telegraphy to regulate the transmission of signals byvarying the field current of the alternatlng current generator which isused as a source of energy.

The function ofthe inductance 1 which be functionally asso may compriseiron, is very important, on the one hand it limits to the desired extentthe energy stored in the auxiliary condenser K whatever the capacity ofthe latter may be; on the other hand it prevents a shortcircuit whichwould have a deleterious effect on the condenser C when the spark gap 6is operative. The resistance r of the charging circuit 1' Z K may beincreased so as to produce a slight lead of the charge on the condenserK over that of C, and thereby overcome the slight interval necessarilyexisting between the operations of the spark gaps e and E. In all cases,one would not think of eliminating the inductance Z by considerablyincreasing 1' and the use of this inductance for the above mentionedpurpose constitutes a feature of the present invention.

It should be noted that the lengths of the waves of the oscillatingcircuits E C S and e [as are not necessarily the same; the waves of thelatter circuit may be selected shorter or longer than those of the maincircuit, according to local requirements.

Although it has been stated above that the period of oscillation properof the auxiliary excitation circuit may be selected arbitrarily withrespect to that of the main circuit, the phenomenon observed in circuitscoupled in resonance may be utilized in order to obtain an auxiliaryvoltage, as high as desired, at the terminals of the main spark gap. Animportant practical advantage is obtained which results in a reductionin the ratio of transformation and the coupling co-eflicient of thetransformer between the auxiliary circuit and the main circuit, wit-houtinterfering with the efiiciency of excitation. For this purpose wearrange, as shown in Fig. 2 an auxiliary capacity K, in shunt to theterminals of the main spark gap E. As long as the spark gap E isinoperative a closed oscillating circuit S O K S, is thereby produced,having a predetermined periodicity, which it is ossible to synchronizewith the excitation circuit K s e. When the latter is rendered operativeand if the constant dimensions are well selected, a high tension orvoltage is produced at the terminals of K and consequently at E so thatthe circuit S C K acts with regard to the circuit K s e as an artificialantenna havin a capacity substantially equal to that of K K is soselected, as to be of low capacity in comparison with that of the maincondenser C so as to limit the energy accumulated in the said capacity Kwhich would be use- 'circuit 8 K s the period of which can al etilesslyspent in the spark gap E when the latter is rendered operative.

A capacity K may be provided across the terminals of 8.

This allows for the provision of a local waysbe; synchronized with thatof the circuit S C K S. This arrangement may be employed when the lengthof connections between 8 and e is considerable (as it may be in somestations) in order to permit of ready synchronization of the circuits 6K s e and S C K S. It will be understood that it is the discharge of thecondenser K through e that produces the vibration of the local circuit 8K s by a phenomenon of impulsion analogous to that used in apparatuscalled wave controllers for controlling receivers.

We claim:

1. A system for generating waves for wireless telegraphy, comprising aprincipal oscillation circuit including a source of energy, a spark gap,a condenser, an inductance; and an auxiliary generating circuit alsoincluding a spark gap, a condenser and an inductance, the inductance ofthe auxiliary circuit being influenced by that of the principal circuit,and the condenser of the auxiliary circuit in serial connection with aresistance and inductance being shunted to the condenser of the maincircuit.

2. A system for generating waves for wireless telegraphy, comprising aprincipal oscillation circuit including a source of energy in the'formof an alternating current generator, a spark gap, a condenser, aninductance; an auxiliary generating circuit including a condenser, aninductance and a spark gap which consists of a pair of sparkelectrodes'and a rotary element between the same, the rotary elementbeing mechanically connected with the said generator, the inductance ofthe auxiliary circuit being influenced by that of the principal circuit,and the condenser of the auxiliary circuit being charged by the samesource of energy from which the principal circuit derives its energy,and a resistance in series with an inductance placed between the sourceof energy and the condenser of the auxiliary circuit.

3. A system for generating waves for wireless telegraphy, comprising aprincipal oscillation circuit including a source of energy in the formof an alterating current generator functionally associated with a dynamoelectric machine generating the current for the field of saidalternating current generator a spark gap, a condenser, an inductance;an an auxiliary generating circuit including a condenser, an inductance,a rotary element provided with projections, and a spark gap formed by apair of electrodes between which said rotary element is moved so as tobring intermittently its projections into opposition to said electrodes,said rotary element being driven from the shaft of the alternatingcurrent generator, and being mechanically connected with the said fieldcurrent generator the inductance of the auxiliary circuit beinginfluenced by that of the principal circuitfand the condenser of theauxiliary circuit being charged by the 7 source of energy of theprincipal circuit, a

resistance in series with an inductance being placed betweenthecondenser of the auxil iary circuit and said source of energy.

4. A system for generating waves for wireless telegraphy, comprising amain oscillation circuitcontaining a source of energy in form of analternator functionally associated with a direct current generatorproducing the field current for the alternator, a spark gap, acondenser, an inductance; and an auxiliary generating circuit comprisinga condenser, an inductance, a pai of electrodes, a rotary elementprovided ithf projections movable between said electrodes to produce.

intermittently a spark gap, said rotary element'being actuated by meansof transmission gears from the shaft of the alternator,

the field current generator for the alternator.

being mounted on the shaft on which the rotary element for the sparkgap. of the auxilw iary circuit ismoimted, the inductance of theauxiliary circuit being influenced by that vof the principal circuit,and the condenser of the auxiliary circuit being charged by the samesource of energy from which the main circuit is charged, a resistance inseries with an inductance being placed between the source of energy andthe condenser of the auxiliary circuit.

inductance; -and an auxiliary generating cir- 5. A' system 'for'generating wayes for, radio telegraphy,compri sing in combination a mainoscillation'circuit containing a spark gap, a condenser, and aninductance; and an auxiliary generating circuit comprising also a sparkgap, an inductance, and a condenser connected with 'the electrodes ofthe spark" ap, .the inductance of the auxiliary circuiting influenced bythat of the main circuit,

and. the condenser of the. auxiliary circuit being charged directlyfronr the source for 'the main circuit through a"resistance andinductance which are placed in series with the auxiliary condenser, saidlast named con denser, reslstance, and lnductance belng 'con-' necteacross the main circuit;

6. A system for generating waves for radiotelegraphy, comprisingaprmcipal os-' cillatlon circuit contaming a-source of electrlcalenergy, a spark gap, a-cond'enser, an

cuit comprising also a spark gap, an inductance, and a condenser, theelectrodes of the auxiliary spark gap being connected with the condenserand auxiliary inductance, the

inductance of the auxiliary circuit being influenced by that of theprincipal circuit, and

pal oscillation circuit which includes a source "of energy, a spark gap,a condenser, an mductance; and an auxiliary generating cir cuitalsoiricluding a spark gap, a condenser,

and an inductance, the inductance of the auxiliary circuit beinginfluenced by that of the principal circuit, the condenser of theauxiliary circuit being charged from the same source from whichthe-principal circuit derives its energy, a resistance in series with aninductance being interposed between the source of energy and thecondenser .of the auxlliary circuit, and a second condenser in theauxiliary circuit being shunted across the inductance of theauxiliarycircuit.

8; A system for generating Wavesfor -wireless telegraphy, comprising aprincipal oscillation circuit which includes a source of energy, a sparkgap, a main condenser, an I inductance,7and a second condenser shuntedto-the electrodes oi the main spark gap; and an auxiliary generatingcircuit also including a spark gap, a condenser, and an inductance, theinductance of the auxiliary circuit being influenced by thatof theprinci-' pal circuit, the condenser of the auxiliary. circuit beingcharged from the same source 'from which the principal circuit derivesits energy, a resistance in series with an inductance beinginterposedbetween the source of energyand the condenser of the auxiliary circuit,and the auxiliary circuit including an additional condenser shuntedacross the inductance oftheauxiliary circuit. I

In testimony whereof we 'aflix our signatures. a

EMILE .GIRARDEAU.. JOSEPH BETHENOD.

